Measurement of restoration success is a challenge, especially in multiple-stressed urban systems. Standard indicators for ecological assessment may be too robust to indicate small but continuous improvements. Thus, we extended a standardized method of the European Water Framework Directive (EU WFD) by additional samplings of macroinvertebrates in the urban Emscher catchment. The aim was to prove whether an additional sampling may add values in the interpretation of restoration success. According to the EU WFD, the Emscher's ecological status and potential were mainly identified as good to moderate regarding biological components of macrophytes and macroinvertebrates, whereas bad regarding fish communities. The additional sampling improved the quality of the biological dataset, because twice as many species of macroinvertebrates were found compared to the WFD method. Hence, the additional sampling allowed a stronger indication for community ordination, and community metrics describing diversity, dispersal and feeding preferences as well as by disentangling the roles of environmental variables. Nevertheless, we concluded that the standardized and simple WFD method was sufficient to capture the most relevant effects. However, if the budget is allowed and information on the species pool, nature conservation or aspects of early indication are needed, it may be useful to implement an additional sampling of macroinvertebrates.

中文翻译：

---

我们是否应该采样超过欧洲水框架指令的要求？案例研究：Emscher 集水区

衡量恢复成功是一项挑战，尤其是在多重压力的城市系统中。生态评估的标准指标可能过于稳健，无法表明微小但持续的改进。因此，我们通过对城市 Emscher 流域中的大型无脊椎动物进行额外采样，扩展了欧洲水框架指令 (EU WFD) 的标准化方法。目的是证明额外的抽样是否可以在解释恢复成功时增加价值。根据欧盟 WFD，Emscher 的生态状况和潜力在大型植物和大型无脊椎动物的生物成分方面主要被确定为良好至中等，而在鱼类群落方面则为差。额外的采样提高了生物数据集的质量，因为发现的大型无脊椎动物种类是 WFD 方法的两倍。因此，额外的抽样为社区协调提供了更强的指示，以及描述多样性、分散和喂养偏好的社区指标，以及通过解开环境变量的作用。尽管如此，我们得出的结论是，标准化和简单的 WFD 方法足以捕捉最相关的效果。但是，如果预算允许并且需要有关物种库、自然保护或早期指示方面的信息，则对大型无脊椎动物进行额外的采样可能是有用的。分散和喂养偏好以及解开环境变量的作用。尽管如此，我们得出的结论是，标准化和简单的 WFD 方法足以捕捉最相关的效果。但是，如果预算允许并且需要有关物种库、自然保护或早期指示方面的信息，则对大型无脊椎动物进行额外的采样可能是有用的。分散和喂养偏好以及解开环境变量的作用。尽管如此，我们得出的结论是，标准化和简单的 WFD 方法足以捕捉最相关的效果。但是，如果预算允许并且需要有关物种库、自然保护或早期指示方面的信息，则对大型无脊椎动物进行额外的采样可能是有用的。